High field magnetization and spin reorientation in Sm2(Fe1−xAlx)17 single crystals

High field magnetization measurements have been performed for single crystals of Sm2(Fe1−xAlx)17, with x = 0.075, 0.093, 0.114, 0.145. The spontaneous magnetization at room temperature lies in the hexagonal c plane. Appreciable anisotropy within the c plane was observed at 4.2 K with the magnetization along the a axis being more than 3% smaller than that along the b axis, even in a field of 10 T. The c axis curve has been found to show a smaller spontaneous magnetization, indicating that the total magnetization vector is not within the c plane but in the plane spanned by the b and c axes. The angle between the magnetization direction and the b axis increases linearly with increasing x. The results are analyzed on the basis of crystalline electric field theory.